Dear Linda & Group, I have been using a mix of equal parts crushed granite (apriximately 1-2 mm diameter) and milled pine bark (5-10 mm) with good results for both bulbs and succulents. The question I have is: Doesn't Alberto's mix dry out too fast? How regular do you have to water and fertilize, since it contains a minimum of organic material? Thanks & Kind regards! Pieter South Africa